Harare, June 27 (bdnews24.com/Reuters) - Zimbabweans began voting in a one-sided presidential run-off on Friday after President Robert Mugabe defied mounting world condemnation and calls to potspone an election which the opposition says is a farce.

Opposition leader Morgan Tsvangirai, who beat Mugabe in the first round of voting in March, withdrew from the run-off last Sunday over violence and intimidation of his Movement for Democratic Change (MDC) supporters by the ruling ZANU-PF party.

Voting began shortly after 0500 GMT and turnout was thin at some polling stations in the capital Harare, unlike the March election when people began lining up from the early hours. Polling is due to end at 1700 GMT.

"I am here to exercise my vote. It does not make a difference for me (that only Mugabe is standing)," Tabeth Masuka said at a polling station in Harare's Avondale suburb.

"I will not be voting, I think it does not make sense to vote when one of the candidates has already withdrawn from that contest," said Terrence Mukumba, a Harare-based bank employee.

The poll has been widely condemned and a security committee of the Southern African Development Community (SADC) called for the vote to be postponed, saying Mugabe's re-election as the only candidate could lack legitimacy.

But Mugabe, 84, planning to extend his 28-year-old uninterrupted rule, remained defiant and even ridiculed African leaders who said he should delay the election.

"Even today they are saying do away with the election, what stupidity is that," Mugabe said at his last campaign rally on Thursday, where he urged people to vote in large numbers.

Mugabe has barred observers from Western countries critical of his government and all but refused entry to hundreds of foreign journalists who were keen to cover the election.

A grouping of local observers has said its members were harassed and intimidated by government supporters and that they would not observe Friday's vote.

Zimbabwe's electoral authorities forged ahead with preparations for the poll, deploying thousands of polling officers across the country and distributing ballot boxes and papers to more than 8,000 polling stations.

Police said they would deploy officers to prevent any trouble.

CEMENT GRIP

Analysts said Mugabe was pressing ahead with the election in a bid to cement his grip on power and strengthen his hand if he was forced to negotiate with Tsvangirai.

Mugabe has said he is willing to sit down with the MDC but would not bow to outside pressure, even from the African Union.

African heavyweight state Nigeria backed the SADC security committee's call for a postponement, saying it was doubtful a credible poll could be held under current circumstances.

"Clearly Mugabe's plan is to be in a stronger position come negotiating day but the whole process lacks legitimacy both locally and internationally," said John Makumbe, a political analyst and long-time Mugabe critic.

Zimbabweans had hoped the run-off would help end a severe economic crisis marked by acute shortages of foreign currency, food, an 80 percent unemployment rate and the world's highest inflation rate, estimated to be two million percent.

A loaf of bread now costs 6 billion Zimbabwe dollars, or 150 times more than at the time of the first round of elections.

The MDC says nearly 90 of its supporters have died in political violence which it blamed on ZANU-PF supporters. Mugabe says the opposition has been responsible for the violence.

Tsvangirai said if Mugabe declared himself president he would be shunned as an illegitimate leader who killed his own people.

The MDC said it feared ZANU-PF would force people to vote, especially in rural areas, ruling party strongholds where Mugabe seemed to have lost his support to the MDC during the first round of voting in March.

"What will happen tomorrow is that people will be forced to vote ... because the military were mobilised to accompany this process," Tsvangirai said in an interview on Thursday with Portuguese radio station Renascenca.

Zimbabwean police said Britain and the United States were backing plans by the MDC and some NGOs to disrupt Friday's vote with violence, including burning down voting tents.

Since the March election, Mugabe has rallied his shock troops, veterans of the 1970s independence war and youth militia, in a violent campaign that critics say has made a free and fair election impossible.